In gentoo opendkim ebuild install config file in /etc/opendkim, not in /etc/mail, but additional opendkim script ( opendkim-reportstats ) search opendkim config in /etc/mail/ Pleade add in src_prepare sed call .... Thank's
+ 16 Jul 2013; Eray Aslan <eras@gentoo.org> opendkim-2.8.4.ebuild: + Fix config file location in opendkim-reportstats - bug #475952 +